A kind of columniform battery cap
Technical field
The present invention relates to a kind of columniform battery cap.
Background technology
Lithium ion battery is high with its specific energy, specific power is large, have extended cycle life, and not containing noxious substance, obtains increasingly extensive application.Especially cylindrical lithium ion battery, its sturdy and durable, good seal, easy connection in series-parallel combination, its many models are identical with the overall dimension of dry cell, ickel-cadmium cell, Ni-MH battery, and as easy as rolling off a log replacement uses, and its use is extensive especially.Therefore improving it, make it safety and reliability, is very significant.
Existing column lithium ion battery generally does positive pole exit with block, the structure of its positive terminal as shown in Figure 1, electrode group 1 ' is contained in box hat 2 ', anode ear 7 ' is had to draw from pole group, be soldered on block base 5 ', the explosion-proof unlatching aluminium film 4 ' of made with aluminum foil is to lower process, welded together with the central point of cover base.Cap head 6 ' above has the steam vent 8 ' of 6 3*3mm, once internal pressure is too high, explosion-proof unlatching aluminium film 4 ' raises up, and pulls open the solder joint with base 5 ' of blocking a shot, and disconnects external the electrically connecting of positive pole, and discharge and recharge stops, and limits dangerous further developing.If internal pressure is high again, aluminium film rupture, gases at high pressure release from steam vent.Decrease internal pressure, prevent blast.This structure is simple, effectively, is convenient to processing, but also comes with some shortcomings.Such as 1, the rigidity of block is fine, when the mutual connection in series-parallel of battery in groups time, just likely multiple battery is all pressed on this block, if be subject to the External Force Actings such as violent vibratory impulse, rigidity is well blocked a shot and external force will be passed on sealing ring 9 ' entirely, and sealing ring 9 ', by large External Force Acting, can change its operating state, airtight quality is caused to decline, the of long duration danger that just there will be leakage.If 2 pressure are too large, crown sink, and is just likely pressed onto unlatching layer below, causes and opens the film rupture of layer aluminium, seal failure.3, six steam vents on block are very large, and like this, when cap head Laser Welding, if solder joint skew, or Workpiece fixing is forbidden, and laser beam directly will be got on explosion-proof unlatching aluminium film 4 ' through steam vent 8 '.If 4, welding energy is too large when caping Laser Welding, burn the danger of cap layer in addition, the laser beam penetrated can burn downwards further opens aluminium film.Because the fusing point of aluminium is more much lower than steel, laser beam is easy to it to burn, and makes cell sealing-structure complete failure.More it is a risk that this damage be can't see in appearance at all, if this battery is loaded battery pack, the electrolyte dry-out caused along with gas leakage leakage, this battery failure, will cause the earlier period damage of whole battery pack.
Summary of the invention
The invention provides the columniform battery cap of a kind of concussion resistibility power, anti-extrusion, anti-burn-through, safety.
The technical solution used in the present invention is:
A kind of columniform battery cap, it is arranged on the sealing part of battery steel shell, comprise cap head and base, packing ring is provided with between described cap head and base, described base is covered with explosion-proof unlatching aluminium film, the junction of described cap head and base is coated with sealing ring, and the side of described cap head has multiple steam vent, it is characterized in that: the side of described cap head is provided with the anti-vibration structure making it have axial stretching.The present invention arranges anti-vibration structure in the side of cap head, makes it have certain axial stretching elasticity, when being subject to External Force Acting, some mechanical jerk power can be released well, alleviate the pressure that sealing ring bears, prevent from destroying sealing ring, improve security performance.
Further, described anti-vibration structure is provided with U-type groove at the side opening of cap head.
Or described anti-vibration structure is that Wave-shaped structural is arranged in described cap head side.
Further, the below of described cap head is placed with one deck overcoat.Overcoat prevents the welding slag when cap head burn-through from dropping and hurts explosion-proof unlatching aluminium film, improves fail safe during assembling.
Further, described steam vent be arranged on cap head side cross-drilled hole or fall hole.One prevents sealing ring from having influence on the normal pressure release of steam vent, two prevent laser beam pass steam vent be mapped to hole under the possibility of explosion-proof unlatching aluminium film.
Further, described cap head and base are direct pressing connections, laser welding is connected or ultrasonic bonding connects.
Further, the center of described explosion-proof unlatching aluminium film is connected with the center weld of base.
Beneficial effect of the present invention: against shock, anti-extrusion, anti-burn-through, improve security performance.
Accompanying drawing explanation
Fig. 1 is the structural representation of existing structure.
Fig. 2 is structural representation of the present invention.
Fig. 3 is the structural representation at cap head place of the present invention.
Fig. 4 is the first structure vertical view of cap head of the present invention.
Fig. 5 is the first structure longitudinal sectional view of cap head of the present invention.
Fig. 6 is the second structure vertical view of cap head of the present invention.
Fig. 7 is the second structure longitudinal sectional view of cap head of the present invention.
Fig. 8 is the third structure vertical view of cap head of the present invention.
Fig. 9 is the third structure longitudinal sectional view of cap head of the present invention.
Figure 10 is the 4th kind of structure vertical view of cap head of the present invention.
Figure 11 is the 4th kind of structure longitudinal sectional view of cap head of the present invention.
Embodiment
Below in conjunction with specific embodiment, the present invention is further described, but does not limit the invention to these embodiments.One skilled in the art would recognize that all alternatives, improvement project and the equivalents that present invention encompasses and may comprise in Claims scope.
With reference to Fig. 2, Fig. 3, a kind of columniform battery cap, it is arranged on the sealing part of battery steel shell, comprise cap head 1 and base 2, be provided with packing ring 3 between described cap head 1 and base 2, described base 2 is covered with explosion-proof unlatching aluminium film 4, the junction of described cap head 1 and base 2 is coated with sealing ring 5, the side of described cap head 1 has multiple steam vent 6, and the side of described cap head 1 is provided with the anti-vibration structure making it have axial stretching.The present invention arranges anti-vibration structure in the side of cap head 1, makes it have certain axial stretching elasticity, when being subject to External Force Acting, some mechanical jerk power can be released well, alleviate the pressure that sealing ring 5 bears, prevent from destroying sealing ring, improve security performance.
Anti-vibration structure of the present invention is provided with U-type groove 11, as Fig. 4, Fig. 5 at the side opening of cap head 1.Described anti-vibration structure can also be that Wave-shaped structural is arranged in described cap head 1 side, as illustrated in figs. 6-11.
The below of cap head 1 of the present invention is placed with one deck overcoat 7.Overcoat 7 prevents the welding slag when cap head 1 burn-through from dropping and hurts explosion-proof unlatching aluminium film 4, improves fail safe during assembling.Described overcoat 7 can be gasket structure.
Steam vent 6 of the present invention be arranged on cap head side cross-drilled hole or fall hole.One prevents sealing ring from having influence on the normal pressure release of steam vent, two prevent laser beam pass steam vent be mapped to hole under the possibility of explosion-proof unlatching aluminium film.Steam vent 6 described in the present embodiment adopts cross-drilled hole, as shown in Fig. 4, Fig. 6, Fig. 8, Figure 10.
Cap head 1 of the present invention and base 2 are direct pressing connections, laser welding is connected or ultrasonic bonding connects.The center of described explosion-proof unlatching aluminium film 4 is connected with the center weld of base 2.
The present embodiment by adopt against shock design, the side of block 1 is provided with anti-vibration structure, increases its telescopic elastic, decrease act on block external force to the destruction of sealing ring 5.By adopt fall hole and welding slag preventing design, steam vent 6 is opened on vertical side, become cross-drilled hole or fall hole, greatly reduce its vertical projection area.Even if laser beam is got on this hole, because projected area is minimum, blocking surface is very large, also cannot throw the inside into, hurt aluminium film below, further increase the fail safe of battery.By adopting anti-extrusion design, changing macropore into aperture, increasing the intensity of cap head 1, improve the anti-extrusion ability of block.Anti-weldingly wear meter by sampling, below cap head 1, add one deck overcoat 7 again, the welding slag fallen down when can stop laser beam burn-through cap head 1 hurts aluminium film below, improves fail safe during assembling.